Author Topic: Prop Testing (Read 3335 times)

Matt Colan · « **on:** April 03, 2009, 07:05:24 PM »

Now that I have my Ares in good trim, I have been testing props. So far here are my results. The Zinger 10-6 didn't seem to work on this plane. It didn't have the drive the Ares needed to get through the maneuvers. The Master Airscrew 10-6 is a good prop, but not as good as the 10-6 Powerpoint prop. This prop has plenty of drive and gets through the maneuvers well, also it gives out more line tension than the Master Airscrew. The props I haven't tried yet is a Zinger 11-5 cut down to a 10-5, and what appears to be a Rev-Up 10-6EW.

I wanted to try the Zinger 11-5 cut because after watching Windy's videos I want to get as big a prop on as I can. I can't get anything bigger than a 10 1/4 on without having adequate ground clearance. Also now there is a wider blade than a regular 10 inch prop. That means it will throw more air. I can also speed the motor up a little bit it seems with a 5 pitch prop getting the east coast stunt run.

Any other ideas for prop testing and your opinions on what I am doing?

Brett Buck · « **Reply #1 on:** April 03, 2009, 07:47:41 PM »

Quote from: Matt Colan on April 03, 2009, 07:05:24 PM

Now that I have my Ares in good trim, I have been testing props. So far here are my results. The Zinger 10-6 didn't seem to work on this plane. It didn't have the drive the Ares needed to get through the maneuvers. The Master Airscrew 10-6 is a good prop, but not as good as the 10-6 Powerpoint prop. This prop has plenty of drive and gets through the maneuvers well, also it gives out more line tension than the Master Airscrew. The props I haven't tried yet is a Zinger 11-5 cut down to a 10-5, and what appears to be a Rev-Up 10-6EW.

I wanted to try the Zinger 11-5 cut because after watching Windy's videos I want to get as big a prop on as I can. I can't get anything bigger than a 10 1/4 on without having adequate ground clearance. Also now there is a wider blade than a regular 10 inch prop. That means it will throw more air. I can also speed the motor up a little bit it seems with a 5 pitch prop getting the east coast stunt run.

Any other ideas for prop testing and your opinions on what I am doing?

"after watching Windy's videos I want to get as big a prop on as I can."

D'OH!

But on to your question - as I recall you have an OS 35s. I think you will likely find that in good air, the 10-6EW will give you more line tension and generally feel more secure. Real hero prop in dead air. However it will whip up furiously in the wind. I don't know if you are going to have the necessary poop to pull a 10-5 - maybe with more nitro (like 15%) - and still have enough breathing room. I would suggest that you try a 10-6 regular blade and add nitro until it feels macho enough. A 10-6 Rev-Up is more like 5.4" anyway. And don't overlook APCs - I would guess the reduced load of spinning an APC is low enough to make the 5" viable, but for sure try that and the 10-6.

Without carving that's about all I can recommend, unless you have a source of Y&O or Clarence Bull Y&Os, or Top Flite 10-6s.

Brett

De Hill · « **Reply #2 on:** April 03, 2009, 08:33:47 PM »

Hi Matt,

Try the RSM 10-6, the new Brodak BY&O 10-6, and the APC 10-5.

RandySmith · « **Reply #3 on:** April 03, 2009, 09:42:17 PM »

Matt great inexpensive props for that motor are the Cyclone 10x5.5 ,10 x 6, cyclone, and Eric's new RSM wood 10 x 6 props are really good

Randy

Matt Colan · « **Reply #4 on:** April 04, 2009, 06:01:24 AM »

Brett, I have a few Top-Flite 10-6s that I haven't tested yet. I was also thinking of cutting down an 11-6 prop to a 10-6. Every time I try a BY&O prop on one plane, it shakes like a rag doll and doesn't give me a lot of drive at all. i heard the RSM 10-6 were good props and they even had a little bit of undercamber in them.

Alan Hahn · « **Reply #5 on:** April 04, 2009, 07:43:13 AM »

Quote from: Matt Colan on April 04, 2009, 06:01:24 AM

Brett, I have a few Top-Flite 10-6s that I haven't tested yet. I was also thinking of cutting down an 11-6 prop to a 10-6. Every time I try a BY&O prop on one plane, it shakes like a rag doll and doesn't give me a lot of drive at all. i heard the RSM 10-6 were good props and they even had a little bit of undercamber in them.

I assume you are using balanced props.

If yes there could be two issues--one the BY&O prop blades are fluttering---there was an issue with the early Brodak versions of the prop where the root of the blade was very thin--dangerously thin in some cases. I think this has been solved in later versions-at least the ones I have seen--and didn't exist in the pre-Brodak BY&O.

Secondly, it is possible that particular prop lets your engine run in an rpm range that resonates with the front end of your plane. If that's the case, then my advice is to stay away from that rpm range (and use another style prop)!

Matt Colan · « **Reply #6 on:** April 04, 2009, 08:19:57 AM »

Quote from: Alan Hahn on April 04, 2009, 07:43:13 AM

I assume you are using balanced props.

If yes there could be two issues--one the BY&O prop blades are fluttering---there was an issue with the early Brodak versions of the prop where the root of the blade was very thin--dangerously thin in some cases. I think this has been solved in later versions-at least the ones I have seen--and didn't exist in the pre-Brodak BY&O.

Secondly, it is possible that particular prop lets your engine run in an rpm range that resonates with the front end of your plane. If that's the case, then my advice is to stay away from that rpm range (and use another style prop)!

I would have to be nuts not to use balanced props on the engines. I have only used the Brodak props once on my planes and my grandfather used it on his Sig Chipmunk that now all is left of it is the tail glued onto the workshop wall.

George · « **Reply #7 on:** April 04, 2009, 08:24:34 AM »

Since he has ground clearance problems, would a three-blade prop be appropriate here?

George

Alan Hahn · « **Reply #8 on:** April 04, 2009, 08:33:01 AM »

Quote from: Matt Colan on April 04, 2009, 08:19:57 AM

I would have to be nuts not to use balanced props on the engines. I have only used the Brodak props once on my planes and my grandfather used it on his Sig Chipmunk that now all is left of it is the tail glued onto the workshop wall.

I don't know what to make of your comment. Are you saying the prop crashed his plane?

Bob Reeves · « **Reply #9 on:** April 04, 2009, 09:49:03 AM »

Think he is talking about the earlier Brodak props that would flutter and vibrate.. The new ones are excelent but Brodak is only making the new version in a few common sizes. If you have read De Hill's prop test in Control Line World you will understand his post above.

Matt Colan · « **Reply #10 on:** April 04, 2009, 10:36:35 AM »

Quote from: Alan Hahn on April 04, 2009, 08:33:01 AM

I don't know what to make of your comment. Are you saying the prop crashed his plane?

No, the prop didn't crash his plane but I was just saying that his Chipmunk crashed. It crashed due to an extreme richening of the engine during the horizontal 8s, when it was on the outside loop. He couldn't recover the plane and it went in 10ft from where I was standing.

Quote from: Bob Reeves on April 04, 2009, 09:49:03 AM

Think he is talking about the earlier Brodak props that would flutter and vibrate.. The new ones are excelent but Brodak is only making the new version in a few common sizes. If you have read De Hill's prop test in Control Line World you will understand his post above.

Bob, that is exactly what I meant by my comment. I have read De Hill's prop test in control-line World and I am thinking of other props while referring to that article.

Matt Colan · « **Reply #11 on:** April 04, 2009, 10:39:38 AM »

Quote from: George Bain on April 04, 2009, 08:24:34 AM

Since he has ground clearance problems, would a three-blade prop be appropriate here?

George

George that would be a good idea, but I don't want to go out spending 50 dollars on a carbon fiber prop. Are there any other cheap 3 blade props anywhere?

Brett Buck · « **Reply #12 on:** April 04, 2009, 11:46:56 AM »

Quote from: Matt Colan on April 04, 2009, 06:01:24 AM

Brett, I have a few Top-Flite 10-6s that I haven't tested yet. I was also thinking of cutting down an 11-6 prop to a 10-6. Every time I try a BY&O prop on one plane, it shakes like a rag doll and doesn't give me a lot of drive at all. i heard the RSM 10-6 were good props and they even had a little bit of undercamber in them.

If you have the Top Flites, try those first. When I was running Fox 35s (and the OS is a lot like an Asian Fox), I always ended back with the Top Flite. I mean, of course, the old "regular blade" Top Flite - although the Power Prop of the same era was sometimes good. It wasn't great at anything but it was decent all the time. Of course at that time there wasn't anything like an APC. I haven't tried enough of the current "Power Point" props to know anything about them.

By BY&O - do you mean the Clarence Bull version or the Brodak version? Makes all the difference in the world. The Brodak version, will apologies to all involved, are not the same animal.

I had forgotten about the RSM prop, that's an even better choice. If nothing else, put it on for appearance judging, because the props I saw were works of art.

It's my expectation that you are going to need at least 5 1/2" of pitch. The engine just falls off too quickly with RPM to run less than that. THAT is why the 20FP and it's ilk provide more performance - it has enough power at high revs to permit the use of 4" of pitch, and that's like climbing the hill in 1st gear instead of 4th gear. Lowering the pitch increases the performance more than increasing the diameter - presuming that your engine has enough power at high revs. Unfortunately, you don't.

There's not a lot you are going to be able to do to modify the 35S to use less pitch, and I don't suggest that you try - if nothing else running at higher revs greatly increases the chances of breaking the crank or destroying the connecting rod. More nitro runs the same risk. More blade area will work in good conditions, but will kill you in the wind. So I think you are going to want a good, intermediate-blade prop like the Top Flite or RSM, or the Y&O or *Bull* Y&O if you can get some. If it was me, I would also do some carving, first trying to *add pitch at the tips* of a Master Airscrew wood or similar, and later trying to make the airfoil look like a Y&O/hand launch glider airfoil. But you have to have some judgement and take a chance of doing something a little dangerous, because if you overdo it the prop might fly apart.

Brett

Alan Hahn · « **Reply #13 on:** April 04, 2009, 03:46:54 PM »

Quote from: Bob Reeves on April 04, 2009, 09:49:03 AM

Think he is talking about the earlier Brodak props that would flutter and vibrate.. The new ones are excelent but Brodak is only making the new version in a few common sizes. If you have read De Hill's prop test in Control Line World you will understand his post above.

Of course just as a clarifying point, I first brought up in this thread fluttering props--and only as comment on one possibility of why Matt's plane was vibrating with the BY&O prop. I am not claiming primacy on the topic however!

Also in my post I said the new Brodak ones and the old B(ull)Y&O's and Y&O's were ok too. Actually the early flat pitch Brodak Y&O props (10-4's for example) were the real flimsy ones, because the prop root is really thin.

It isn't clear if fluttering was the case or not--I don't think Matt explicitly said that but it is easy to miss things in posts, I do it all the time

/ The only way to know would be to observe the blade tips. But that is also a scary thing to do if the prop is indeed fluttering.

Steve Helmick · « **Reply #14 on:** April 04, 2009, 08:03:54 PM »

I'd definitely try the TT Cyclone and RSM props. And don't be changing props just for Appearance Judging. Technically, it's not allowed, unless you break the prop. This is to prevent folks from wowing those gullible Judges with specially finished props that never get flown, taking off the wheelpants, etc.

Steve

"10. Appearance. Models shall be judged for appearance complete and ready to fly. After model has been judged, nothing will be removed from or added to the model which, in the judge's opinion, changes in any manner the appearance of the model from the way it was when presented for appearance judging. However, during an attempt for official flight after the contestant has begun to crank the engine, if it becomes necessary to remove the propeller spinner for change of propeller, etc., then it is permissible to leave off the spinner for that particular flight. Any damage to the model after...."

Brett Buck · « **Reply #15 on:** April 04, 2009, 08:08:57 PM »

Quote from: Steve Helmick on April 04, 2009, 08:03:54 PM

I'd definitely try the TT Cyclone and RSM props. And don't be changing props just for Appearance Judging. Technically, it's not allowed, unless you break the prop. This is to prevent folks from wowing those gullible Judges with specially finished props that never get flown, taking off the wheelpants, etc.

I was kidding, of course. But I could argue it's a trim adjustment. I *could* fly with that prop, and no one is going to make you get the airplane judged again if you switch props.

Brett

Matt Colan · « **Reply #16 on:** April 04, 2009, 08:28:47 PM »

Quote from: Steve Helmick on April 04, 2009, 08:03:54 PM

And don't be changing props just for Appearance Judging. Technically, it's not allowed, unless you break the prop. This is to prevent folks from wowing those gullible Judges with specially finished props that never get flown, taking off the wheelpants, etc. Steve

"10. Appearance. Models shall be judged for appearance complete and ready to fly. After model has been judged, nothing will be removed from or added to the model which, in the judge's opinion, changes in any manner the appearance of the model from the way it was when presented for appearance judging. However, during an attempt for official flight after the contestant has begun to crank the engine, if it becomes necessary to remove the propeller spinner for change of propeller, etc., then it is permissible to leave off the spinner for that particular flight. Any damage to the model after...."

Well I don't think I am going to the Nats now since my parents aren't too thrilled with my grandfather and I going out there by ourselves, and I can't drive yet. But now we are looking at going to Brodaks. Still has appearance judging, but your comment reminded me of that.

john e. holliday · « **Reply #17 on:** April 05, 2009, 02:13:09 PM »

If Grandpa is in good health the trip might be great for him. There is an EMT not too far just in case. Also a whole bunch of dedicated modelers/competitors that will help you keep him out of trouble. Also you can learn a lot in one trip to the NATS. Have fun, DOC Holliday

Matt Colan · « **Reply #18 on:** April 05, 2009, 07:08:24 PM »

Quote from: john e. holliday on April 05, 2009, 02:13:09 PM

If Grandpa is in good health the trip might be great for him. There is an EMT not too far just in case. Also a whole bunch of dedicated modelers/competitors that will help you keep him out of trouble. Also you can learn a lot in one trip to the NATS. Have fun, DOC Holliday

DOC, we are going to Brodak instead of the Nats for this year. I can't drive and he doesn't like driving for 800 miles with only him driving. Also he really has no idea where he is going, but going to Brodak he knows where he is going. I can learn a lot at Brodak also, since it is 5 days. I've also heard that it is the best, most fun, and biggest control-line meet on earth.

Nats will be 2011

Tony Clifford · « **Reply #19 on:** April 06, 2009, 05:12:38 AM »

Just a thought, I am also running an OS .35S and after trying out various propeller combinations, have found the Bolly 10.5 x 5 to give great performance.
Except for the Fox .35, this propeller also gives a good run on most early .35 type motors.
Give it a go, Cheers - Tony.

Matt Colan · « **Reply #20 on:** April 06, 2009, 06:14:36 AM »

Quote from: Tony Clifford on April 06, 2009, 05:12:38 AM

Just a thought, I am also running an OS .35S and after trying out various propeller combinations, have found the Bolly 10.5 x 5 to give great performance.
Except for the Fox .35, this propeller also gives a good run on most early .35 type motors.
Give it a go, Cheers - Tony.

I would try it but I don't have enough prop clearance for anyhting more than a 10 1/4 inch prop.

Tony Clifford · « **Reply #21 on:** April 06, 2009, 11:47:41 PM »

Matt, if you now have 2" wheels, just go up to 2 1/4" or even 2 1/2" - or maybe bend the undercart closer together (unless it's wing mounted).
Just a thought.
Cheers, Tony.

Matt Colan · « **Reply #22 on:** April 07, 2009, 02:28:51 PM »

Quote from: Tony Clifford on April 06, 2009, 11:47:41 PM

Matt, if you now have 2" wheels, just go up to 2 1/4" or even 2 1/2" - or maybe bend the undercart closer together (unless it's wing mounted).
Just a thought.
Cheers, Tony.

I am running 2 1/4 inch wheels now and I can't change the wheels on it.